Unless otherwise indicated herein, the description in this section is not prior art to the claims in this application and is not admitted to be prior art by inclusion in this section.
There are provided techniques in which inks are arranged in an order specified in a predetermined parameter to be discharged so as to ensure an improved quality of an image formed by these inks (image quality). One technique specifies the ink order based on a ratio of a surface tension to a viscosity. Another technique specifies the ink order based on the viscosities.